It may sound like an easy swap since the inlet/outlet of the borla should slip fit the 3.0" loudmouth pipes. However, this was not the case and I now know why few people run this setup and those that do usually have the whole sytem welded up at a shop.

Anyway, I finally got the XR-1 muffler bolted in using 3.0" diameter band clamps and some weather proofing to seal the slightly different size between the inlet/outlets and the loudmouth piping.

Definitely worth the trouble! I love the sound. Quiets down the setup at idle, but also gets very loud with more throttle. It gives a deeper tone, and there is much less drone and rasp compared to the SLP bullet I. Sounds less like a truck and more like a muscle car. I will have a sound clip up soon.